Nova Patents
US7268481B2

Field emission display with smooth aluminum film

Summary by NHIP

Field emission display with nitrogen-doped aluminum

The field emission display device includes a cathode member with a single aluminum layer incorporating nitrogen to reduce hillock formation. This nitrogen-doped layer sits between the baseplate and an insulating layer, maintaining resistivity below 12 μΩ-cm while enabling smooth electron emission.

Claim Score by NHIP

Read claim 8, the broadest

Abstract

This invention provides a conductive aluminum film and method of forming the same, wherein a non-conductive impurity is incorporated into the aluminum film. In one embodiment, the introduction of nitrogen creates an aluminum nitride subphase which pins down hillocks in the aluminum film to maintain a substantially smooth surface. The film remains substantially hillock-free even after subsequent thermal processing. The aluminum nitride subphase causes only a nominal increase in resistivity (resistivities remain below about 12 μΩ-cm), thereby making the film suitable as an electrically conductive layer for integrated circuit or display devices.

US7268481B2, drawing sheet 1
Sheet 1 of 5

Term

Term ended

Expired 4 February 2019, 7.6 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

13 claims: 3 independent, 10 dependent

  1. 1
    A field emission display device, comprising:a faceplate and a baseplate;a luminescent phosphor coating applied to a lower surface of the faceplate to form phosphorescent pixel sites;and a cathode member formed on the baseplate to form individual electron-emission sites which emit electrons to activate the phosphors, the cathode member comprising: a semiconductor layer overlying a portion of the baseplate, the semiconductor layer including an emitter tip;an insulating layer formed above the baseplate and surrounding the tip;a single aluminum layer surrounding the tip between the baseplate and the insulating layer, the single aluminum layer incorporating nitrogen substantially uniformly throughout the single aluminum layer to reduce hillock formation, wherein the single aluminum layer is the only layer of aluminum between the baseplate and the insulating layer;and a conductive layer surrounding the tip and overlying the insulating layer.
  2. 8
    Broadest claimClaim Score 71, broad(NHIP)A field emission cathode, comprising:a substrate;an emitter tip formed on the substrate;a dielectric layer formed above the substrate and surrounding the tip;single aluminum film overlying said substrate and surrounding said emitter tip, said single aluminum film including nitrogen distributed substantially uniformly throughout said film to reduce hillock formation and said single aluminum film comprising an aluminum nitride subphase, wherein the single aluminum film is the only layer of aluminum between the substrate and the dielectric layer;and a gate layer formed above the dielectric layer and surrounding said tip.
  3. 11
    A field emission cathode, comprising:a substrate;an emitter tip formed on the substrate;a dielectric layer formed above the substrate and surrounding said tip;single aluminum film overlying said substrate and surrounding said emitter tip, said single aluminum film including nitrogen distributed substantially uniformly throughout said film to reduce hillock formation, wherein the single aluminum film is the only layer of aluminum between the substrate and the gate layer;a gate layer formed above the dielectric layer and surrounding said tip;and a layer of grid silicon between the dielectric layer and the gate layer.
Independent claims3